Abstract: A net member is stretched over a frame for a seat and backrest of a chair. An engagement member attached to the end of the net member is inserted into an engagement groove on the lower surface of the basic frame. A binding frame is pressed onto the lower surface of the basic frame and the net member is fixed between the basic frame and the binding frame by the engagement piece.

Abstract: A seismic isolation apparatus is structured such that a pair of seismic isolation mechanisms are formed each having a pair of upper and lower clamping members formed in the shape of a rectangular frame, wherein upper and lower roller guide surfaces, in each of which a longitudinal central portion is formed as a concavely arcuate curved surface and portions respectively extending therefrom are formed as convexly arcuate curved surfaces, are formed on the four sides of the upper and lower clamping members, and wherein rollers each having a circular cross section are respectively interposed between the upper and lower roller guide surfaces. The pair of seismic isolation mechanisms are installed by being superposed on top of each other such that the rolling directions of the rollers in the two seismic isolation mechanisms are perpendicular to each other.

Abstract: A base isolator has four base isolation units placed at four corners between a floor slab and a floor plate. Each base isolation unit has a middle plate, a lower support body which is rotatable in a first direction on the lower side of the middle plate, and an upper support body rotatable in a second direction on the upper side of the middle plate. The upper support body and the lower support body each have mutually eccentric rollers. The middle plates of the four base isolation units are separated from one another so that the plates can be independently displaced or moved.

Abstract: A passive vibration-damping unit in which movable upper members with a weight mounted thereon are superposed on fixed lower members with roller members interposed therebetween is installed in a highest story of a high-rise building. An active vibration-damping unit for actively causing the movable upper members of the passive vibration-damping unit to move in a shaking manner by means of a servo motor is incorporated in the passive vibration-damping unit. When the vibration of the building has occurred, the weight is allowed to move forcibly in the vibration-damping direction by means of the active vibration-damping unit. When the vibration has reached a limit value of the relative displacement of the active vibration-damping unit or a limit value of the torque of the servo motor, only the operation of the passive vibration-damping unit is continued. When the vibration has subsided to a certain extent, the active vibration-damping unit is operated again.

Abstract: A plurality of rods each having a bit at a front end are disposed in parallel to one another so that adjacent bits are displaced to some extent forward and backward, and a striking device operatively connected to each of the rods includes a striking block. The striking block includes a single cylinder block having a plurality of cylinder tubes, and a striking piston is slidably fitted into each of the cylinder tubes. The striking block further includes a change-over valve for changing over between a forward movement and a backward movement of each striking piston. A rear end of each rod is connected through an adapter to a shank rod which is connected to the striking device. In the striking device, a spring is provided between a bearing holder which holds the shank rod rotatably and the adapter to push the rod in a forward direction. When the bit is not reached the rock, the rod is pushed forward by the spring to hold the shank rod at a position before the striking point.

Abstract: A rock crushing device which crushes a rock by an expandable member which is, after being inserted into a borehole formed in the rock, expanded by pressure of a liquid material injected thereinto, including a liquid pressure measuring device provided in a liquid supply hose and a processor connected to the liquid pressure measuring device for processing the liquid pressure converted into electric signals and the time interval during which the liquid pressure is measured, wherein a valve provided in the liquid supply hose is controlled to be closed when the value of the value corresponding to the decreased pressure of liquid material of the liquid pressure measured by the processor exceeds a predetermined value.

Abstract: A rock drill for drilling a plurality of arrayed continuous bores includes a plurality of rods positioned so as to be able to drill several arrayed continuous bores, a rotating member to give rotation to the rods and a single percussion member which imparts percussive force to the plurality of rods. The plurality of rods may be passed through integrally formed rod guides by connecting several cylindrical members juxtaposed in parallel. The guide rod may optionally include, at its rear end, a swivel which also acts as a rod holder.

Abstract: A method of excavating a tunnel in bedrock, including the steps of boring an outer peripheral slot in the bedrock, boring a plurality of horizontal slots in a bedrock section surrounded by the outer peripheral slot such that the bedrock section is divided into a plurality of bedrock portions by the horizontal slots, boring a plurality of vertical slots in one of the bedrock portions such that the one of the bedrock portions is divided into a plurality of bedrock blocks by the vertical slots, removing the bedrock blocks from the bedrock so as to define a working space, and providing an excavator in the working space such that the remaining ones of the bedrock portions are sequentially excavated by the excavator.

Abstract: A method and an apparatus for building a thin lining on a tunnel to be excavated. The method includes the steps of boring a slot along an outer periphery of a cross section of the tunnel, filling lining material into the slot so as to form the lining material into the thin lining and removing bedrock surrounded by the thin lining so as to expose the thin lining. The apparatus includes a boring device for boring a slot in the tunnel and an injection device for injecting lining material into the slot. The boring device further includes a hollow frame, a plurality of rods fitted axially movably into the hollow frame, and a drive mechanism for rotating the rods and striking rear ends of the rods.

Abstract: A method and an apparatus for excavating pile holes of various shapes, including a pile hole with a widened bottom and a pile hole with a widened top and widened bottom, by means of an excavating bit and widening bits.

Abstract: A soil transporting vehicle for pressurized receiving and transporting of soil excavated by a shield machine. The vehicle includes a cylindrical soil container having a first opening and a second opening aligned along the longitudinal axis and being pressure-resistant. A soil conveying mechanism is arranged in the container adjacent to the opening for moving the soil axially. A chassis rotatably supports the container and a drive mechanism is provided for rotating the container about its axis from a soil introduction position where the openings are directed upwardly and a soil discharge position where the openings are directed downwardly. An inlet for introducing gas under pressure and a pressure regulating valve are provided on the soil container. The pressure is regulated to be substantially equal to that of the pressure compartment of the shield machine. A compressor is connected with the gas inlet.

Abstract: Method and apparatus for determining angular and transversal displacements of a shield machine and a succeeding pipe relative to a pre-determined schedule central axis of a tunnel to be constructed by pipe-jacking tunneling which includes providing on the shield machine a first light emitter which emits rearwardly a light beam along the central longitudinal axis of the shield machine and a reference position on the axis of the shield machine, projecting the light beam to a pair of targets, each having a scale and being provided in a succeeding pipe spaced from each other by a predetermined distance along the central longitudinal axis of the succeeding pipe to form light spots on the targets, projecting to the pair of targets a light beam emitted from a second light emitter along the scheduled central axis of the tunnel to be constructed to form further light spots on the targets with the second light emitter being located at the rear portion of the tunnel, and reading the light spots and the further light spo